High ampere-rated circuit breakers such as described within U.S. Pat. No. 3,073,936 entitled "Electric Circuit Interrupter" are currently employed within industrial manufacturing facilities to protect the electric equipment and buildings from damage due to the occurrence of overcurrent conditions within the electrical distribution system. Earlier designs of such circuit breakers employed thermal -magnetic trip units to determine the overcurrent conditions and to articulate the circuit breaker operating mechanism to separate the circuit breaker contacts to interrupt the associated electric circuit. Later designs employed electronic trip units and employed so-called "flux shifters" to articulate the operating mechanism upon signal from the electronic trip unit. One example of an early analogue trip unit is found in U.S. Pat. No. 3,761,778 entitled "Static Trip Control Unit for Electric Circuit Breaker".
Such robust circuit breakers remain in operation to this date without needing replacement or repair. However, the advent of the digital circuit interrupters described within U.S. Pat. No. 4,672,501 entitled "Circuit Interrupter and Controller Unit", allows several circuit breakers within a common electrical distribution system to communicate with each other. It would be beneficial to convert existing circuit breakers having earlier trip units to digital trip units without having to dismantle the circuit breaker in the process.
One purpose of the invention is to provide a conversion unit that will enable circuit breakers to employ digital trip units without having to dismantle the circuit breaker operating components as well as providing electric switches on existing flux shifter trip devices to allow the operating status of the circuit breakers to be communicated.